Comet Interceptor
A mission that will wait in space for a pristine comet, then split into three to meet it.
Key facts
- Agency
- European Space Agency (ESA), with JAXA
- Type of mission
- Comet flyby (three spacecraft)
- Target
- A comet not yet chosen, ideally one entering the inner Solar System for the first time
- Launched
- Planned for 2029
- Status
- In development
Every comet visited so far has been to the inner Solar System many times before, and the Sun's heat has changed it. Comet Interceptor is designed to meet one that has never done so: a comet arriving from the distant Oort cloud for the first time, still carrying ice and dust almost unchanged since the planets formed. It might even meet an interstellar object passing through from another star.
Waiting in space
Such comets are usually found only months or a few years before they pass the Sun, too late to build and launch a spacecraft. So Comet Interceptor will launch first, planned for 2029 together with the European Ariel telescope, and wait at a point in space about 1.5 million kilometres from Earth, away from the Sun. When telescopes find a suitable comet on a reachable path, it will set off.
Three in one
Shortly before the encounter, the main spacecraft will release two smaller probes, one of them built by JAXA. The main craft stays at a safe distance, while the probes fly closer through the dust, so the comet can be seen from several directions at once, giving a three-dimensional view of its nucleus, gas and dust.
Why it matters to meteorites
A fresh comet's dust is the closest thing to the raw material of the outer Solar System. Comparing it with interplanetary dust and the most primitive micrometeorites collected on Earth will test whether some of that material reaches us.
Key dates
| Date | What happened |
|---|---|
| 2029 | Planned launch with the Ariel space telescope. |
See where this mission fits among all the others in the mission timeline.
Did you know?
Comet Interceptor is the European Space Agency's first fast-class mission, built in a shorter time and to a smaller budget than usual.
Its target may not even have been discovered yet when it launches.
Related pages
Comets connected with this mission: 'Oumuamua, the first interstellar visitor, Comet Borisov, Comet 3I/ATLAS. See all comets.